Bacteriologie Flashcards
Virulence factors S. aureus
Toxins: cytolytic, enterotoxins, exfoliative toxins
Enzymes: coagulase, hyaluronidaselipase, fibrinolysis, catalase
bad bacteria in microbiome
Neisseria meningitidis
streptococcus pneumoniae
s. aureus
virulence definition
degree of pathogenicity (ability to produce disease) of the microbe
virulence factors, examples
adhesins, invasins, capsule, toxins, enzymes, pili
gram+ bacteria divided into 2 subgroups
cocci
bacilli
what type of bacterium is N. meningitidis
gram negative diplococcus
what does bromelia burgdorferi cause?
lyme disease
wat is serologie?
het aantonen van immunoglobulinen tegen agens
welke vormen hebben deze soorten respectievelijk: coccus, baccillus, spirochetes
sphere, rod, spiral
what is MIC?
minimal inhibitory concentration –> sterkste verdunning waarbij bacterie niet meer groeit
voorbeelden moeilijk kwetsbare bacteriën
mycobacterium, mycoplasma, chlamydia, legionella
what kind of bacterium is N. meningitidis
gram negative diplococcus (meningococcus)
4 steps of invasive meningococcal disease (IMD):
- colonization
- invasion epithelium
- invasion blood (septicaemia)
- dissemination (to CSF)
4 results meningococcemia (meningococci in bloodstream)
- sepsis
- rash
- disseminated intravascular coagulation (DIC); abnormal blood clotting
- meningitis
what determines meningococcal serogroup, and how many are there?
polysaccharide capsule
13
2 typing methods for N. meningitidis
phenotype and genotype
annotation for N. meningitidis
Example: Nm: B:P1.7,4:F5-1
what methods can be used in genotype typing for N. meningitidis, and what do they do?
- multi locus sequence typing (MLST), sequencing of 7 loci
- ribosomal MLST, sequencing of 53 loci
these methods assign numbers to alleles
what does the sequence type (ST) of N. meningitidis say?
the combination of allele numbers, assigned by MLST
what is a singleton?
a strain that doesn’t belong to a certain clonal complex (CC, a complex matching the central genotype)
what clonal complexes (CC) overrepresented in patients with IMD
CC41/44 & CC32
What clonal complexes are overrepresented in carriers
CC53 & CC35 (no capsules, important virulence factor)
why is there no MenB vaccine?
CPS of B is poorly immunogenic; it is identical to sialic acid in nerve tissue
what does Factor H binding protein (FHbp) do?
enables microbe to bind factor H (from complement) enabling bacterial survival in blood
what is an important AMP and what does it do
Lactoferin; pulls away iron from pathogens
what is GAS
Group A Streptococcus (Streptococcus pyogenes)
what causes impetigo?
S. aureus: exfoliated toxin
GAS
major component of cell wall S. aureus
protein A
what does S. aureus toxin panton valentine do, and what kind of toxin is it?
destroys leukocytes, exotoxin
what kind of bacterium is S. pyogenes (GAS)
gram positive, from chain structures
exotoxins secreted by GAS
SPE: A, B and C